Suppresser



March 10, 1936. P. o. STEWART SUPPRESSER Filed MaFCh 2l, 1934 /Af VEN T0@ @www lm 5y @am 7 C ra/M51@ Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE 10 Claims.

My invention relates to a new and improved suppresser for suppressing undesirable electrical oscillations which are produced by the ignition system of an automobile so that said oscillations will not injuriously affect the reception of. a radio receiving set which is connected to the storage battery of an automobile.

One of the objects of my invention is to provide a universal suppresser or choke, which can be readily applied to all of the standard spark plugs which are now in use in American automobiles.

Another object of my invention is to provide the improved suppresser with certain auxiliary parts which will make it universally applicable to all standard makes of American automobiles.

Another object of my invention is to provide simple, compact and efficient means for varying the inductances of the various choke coils which are used as suppressers.

Other objects of my invention will be set forth in the following description and drawing which illustrate a preferred embodiment thereof, it being understood that the above statement of the objects of my invention is intended to generally explain the same without limiting it in any manner.

Fig. 1 is an elevation showing the improved suppresser applied to a spark plug.

Fig. 2 is a vertical sectional view through the suppresser.

Fig. 3 is a sectional View along the line 3 3 of Fig. 2.

Fig. 4 is a top plan View of the suppresser.

Fig. 5 is a sectional view on the line 5 5 of.

Fig. 1.

Fig. 6 is an elevation showing the application of the auxiliary parts to the suppressor.

Figs. 6a and 6b show certain details.

As sho-wn in Figs. 1 and 2, the suppresser comprises an outer shell or casingl, which is made of a phenol-formaldehyde condensation resin or other suitable insulating material which can be readily molded or worked. The top of the casing l is integral therewith and the bottom of said casing is provided with a cover 2 which is also made of any other suitable insulating material.

The top of the casing I is integral with a central core 3, which is also made of said resin and said core extends substantially to the cover 2. The choke coil C is wound between the inner Wall of the casing l and the core 3.

The choke coil is separated from the top and bottom of the casing, by insulation 4, which is made of suitably treated paper or the like. The choke coil C is made of any suitable wire, such as copper wire of .004 gauge. This wire is provided with a thin covering of enamel.

The choke coil C is of standard construction.

In the practical manufacture of the choke coil, the wire is rlrst wound upon a paper tube P. A single helical coil of wire is wound upon the paper core or tube P, and a piece of insulating paper is then formed into cylindrical shape and it is applied over said iirst helical layer of wire, and said initial intermediate paper sheet is then suitably secured into position, by a suitable adhesive. The wire is then formed into a second helix over said first paper sheet. 15

A second sheet of paper is then applied over the second helix, and this process is continued until the choke coil has been built up to the proper number of layers of turns, each pair of layers having an intermediate sheet of insulat- 20 lng paper.

The end insulation 4 comprises a series of paper layers which are extensions of the intermediate layers which are used in forming the choke coil C. When this coil has been completed, 25 it is slipped over the core 3. The core 3 is internally threaded, in order to receive an externally threaded stud 5, which projects from the top of the casing. A nut 6 is mounted upon the externally threaded stud 5 and this nut E clamps a 30 stamped metal lug l, against the top of the cas` ing. The lug 'l is provided with an extension la which fits into a depression which is formed between upstanding lugs la of the casing l Said projections la are also made of a phenol-form- 35 aldehyde condensation resin and the extension 'la ts snugly in said depression.

'Ihe choke coil C is provided with a top lead 8 which passes through a hole in the top of the casing, and said lead is bent horizontally so as 40 to overlie the extension la and the horizontal branch of said lead 8 is soldered to the top of the lug la. This soldering, together with the fit of the extension 'la in the recess between the projections la, prevents the lug 'l from turning 45 when the nut 6 is applied. The nut 6 can also be connected by solder to the lug 1 so that the members 6 and 'l are held against turning on the stud 5, after the assembly has been com pleted. 50

The cover 2 is held in position by means of a dual threaded connector 9, which is provided with external ribs I0, in order to dissipate the heat which is conductively transmitted to the connector 5, from the spark plug. The connector 55 9 is provided with an externally threaded projection Ia., which enters an internally threaded recess in the core 3. The choke coil is provided with a lower lead 8a, which passes through a hole in the-cover 2 and said lead 8a. passes over and is soldered to the extension I2a of the metal lug I2. The extension I2a fits between projections Za of the cover, and said projections 2a, correspond to the projections Ia which have been previously described.

The lug I2 is clamped into position against the cover 2 by the turning of the projection Ia in the internally threaded recess of the core 3. Likewise the lug I2 is connected to the adjacent flange Illb of the connector 9 by means of solder, and since the wire or lead is also connected to the extension I2a by means of solder, the parts are held together without any danger of relative movement, after the assembly has been completed.

The interior of the connector 9 is provided with a thread Ill and with a second thread Ida. The pitch of thread III corresponds to what is known in the trade as gg. That is, the pitch of said thread is als? (one thirty-second) of an inch and it is adapted to receive a Nov 10 screw or stud. The thread Ida corresponds to what is known in the trade as Tg3- That is', the pitch of thread Ida is @la (one thirty-second) of an inch and it can receive a No. 8 screw or stud.

Referring to Fig. 1, this shows a spark plug S having the usual terminal which is externally threaded. In standard American practice said terminals are either 5% or 3%. A 15% terminal can be received in thread I4 and an 5% terminal can be received in thread Isa, so that the suppresser can be universally applied.

Fig. 3 shows means for regulating the inductance of the coil. As shown in Fig. 3, the interior wall of the casing I may be provided with recesses l5, and the core 3 may be provided with recesses It. Magnetic cores I'I and Ila., in any desired number, may be inserted into said recesses I5 and I5. These magnetic core members are made of soft iron and they serve to vary the inductance of the choke coil.

The core members I'I and Ila. are preferably made of minute iron particles which are connected by means of particles of said condensation resin or other suitable material, in order to form molded masses of cylindrical shape. These core members provide higher magnetic leakage for the high frequency component of the ignition current, so that the inductance of each suppresser can be varied as desired.

A thimble I8, having an internally threaded recess in its bottom wall, can be threaded upon the stud 5. This thimble I8 provides a connector of the socket type for receiving the wire from or to the ignition coil, when the `device is used for connecting the ignition coil to the distributor. rI'he thimble I8 provides a socket connection in any desired location in which the device may be used.

Instead of using a connector of the socket type I8, an internally threaded thimble I9 may be screwed over the stud 5, as shown in Fig. 6a.

The thimble I9 is provided with a flange Illa and a forked terminal of the Rajah type may be placed under the ange I9a in order to connect with the stud 5. Other types of connectors may be slipped over the thimble I9 to rest upon the flange I9a.

In order to install the suppresser upon either the distributor or the ignition coil, a threaded stud 20 can be inserted into the part of member 9 which has thread Ia.. A split bushing 2l can be threaded on the bottom portion of the stud 2E). The split bushing 2| is provided with a head 2id.

The stud 2) is of substantially cylindrical shape, and it is provided with an outer thread of uniform width to its bottom. The stud 20 can rst be screwed into that part of member 9 which has thread Ida. rIhe split bushing 2l can then be located upon said stud 2G. The split bushing 2l is then inserted into the socket of the distributor or of the ignition coil, and the suppresser can then be turned in the clockwise direction.

The internal thread of the split bushing 2i is l inwardly tapered. When the suppresser I is turned, the stud 2li is pushed into the inwardly tapered thread of the bushing 2l, so that the bushing 2l is expanded in order to t tightly intol the corresponding socket.

Instead of using the split bushing 2|, I can use the internally and externally threaded bushing 23, for making contact with coils or the like which have threaded openings in their shells for making connection.

The improved suppresser can be applied at any desired number of locations in the ignition system of an automobile, as referred to more particularly in my application led of even date.

It will be noted that the members Il and I'Ia. can be inserted into the device, or removed from the device, by merely removing the cover 2.

While I have shown an inductive type of suppresser, it is well known to use suppressers having high resistances and the connector I9 could be used with any type of suppresser, and a number of the features of the invention are not limited to the use of an inductance or choke.

For convenience, the threads I4 and Illa may be specified as being different threads, although said threads have the same pitch, in the specic embodiment which has been illustrated.

In order to illustrate the parts more clearly, I have not shown the members la and 8a fitting snugly in the recesses which are provided between the pair of members la, and the pair of members 2a. In -actual practice there can be a snug lit of I said members la and Sa between the corresponding projections Ia and 2a. When I specify that core 3 extends from wall I, I do not wish to be limited to a construction in which members I and 3 are integral or connected to each other.

I have shown a preferred embodiment of my invention, but it is clear that numerous changes and omissions can be made without departing from its spirit.

I claim:

1. A suppresser having a casing and a choke coil located within said casing, said coil having a core made of material which has low magnetic permeability, said casing having at least one recess in which a magnetic leakage member is located. I

2. A suppresser comprising a casing having a core, a choke coil located in said casing between said core and the inner wall of said casing, said coil having a core made of material which has lowV magnetic permeability, said core and said inner wall having recesses in which magnetic leakage members may be located.

3. A suppresser comprising a casing having a longitudinal Wall which is integral with an end said walls and said core being made of insulating material, a choke coil located between said core and the inner surface of said longitudinal wall, a cover located at one end oi the casing, and a connector having a threaded projection which passes through said cover and which enters a correspondingly threaded recess of said core, said connector having a part which is external to said cover, said external part having a pair of recesses which are internally threaded, the outer recess having a greater diameter than the inner recess.

4. A suppressor having a casing, said casing having a longitudinal wall which is integral with an end wall, said casing also having a core, a choke coil located between said core and the inner surface of said longitudinal wall, said choke coil having a terminal which passes through an opening in said end wall, an external metal member which is located adjacent said end wall and to which said le-ad is connected, a threaded metal member which passes through said external member and which enters a correspondingly threaded recess in said core, and a nut mounted on said threaded metal member and clamping said external metal member.

5. A suppresser having a casing, said casing having a longitudinal wall which is integral with an end wall, said casing also having a core, a choke coil located between said core and the inner surface of said longitudin-al wall, said choke coil having a terminal which passes through an opening in said end wall, an external metal member which is located adjacent said end wall and to which said lead is connected, a threaded metal member which passes through said external member and which enters a correspondingly threaded recess in said core, and a nut mounted on said threaded metal member and clamping said external metal member, and means located at the exterior of said end wall and limiting the turning of' said external metal member.

6. A suppresser having a casing, said casing having a core which extends from an end wall of said casing, a choke coil located between said core and the inner surface of said casing, an externally threaded member connected to said core and projecting from one end of said casing, said externally threaded member having one terminal of said coil connected thereto, and a second member connected to said core and projecting from the other end of said casing, said second member having the second terminal of the choke coil connected thereto, said second member having internally threaded recesses of different diameter, the outer recess having a greater diameter than the inner recess.

7. A suppressor comprising a casing made of insulating material and having a longitudinal wall which is integral with an end wall of said casing, a core made of insulating material and integral with said end wall, said casing having a cover at its other end, a choke coil located between said core and the inner surface of said longitudinal wall, said choke coil having a first terminal which passes through an opening in said integral end wall and said choke coil having a second terminal which passes through an opening in said cover, metal contact members located at the outer surfaces of said end wall and of said cover, and having the terminals of said choke coil connected thereto, an externally threaded member which is connected to said core and which projects beyond said integral end wall, a nut mounted upon said externally threaded member and clamping the adjacent metal contact member against the adjacent integral end wall, a second member having an externally threaded projection which passes through the adjacent metal contact member and through the cover and which enters said core, said second member having a head which clamps the adjacent metal contact member in position, the outer end of said second member having a pair of internally threaded recesses which are of different diameters, the recess having the greatest diameter being outermost.

8. A suppresser having a casing and a choke coil located within said casing, said casing being provided with displaceab-le magnetic leakage means whereby the reactance of the choke coil may be varied, said coil having a core made of material 'which has low magnetic permeability.

9. A suppresser having a casing and a choke coil located within said casing, said casing being provided with magnetic leakage means, said coil having a core made of material which has low magnetic permeability.

10. In a suppresser for the secondary circuit of an ignition system for an internal combustion engine, an insulating casing having connector terminals at each end, one of said connectors having a pair of internally threaded recesses, said recesses having respectively different threads, a threaded extension engaging the thread of one of said recesses, and an internally tapered threaded split bushing for attaching said casing to a p-art which is included in said secondary circuit.

PATTERSON O. STEWART. 

